The overall objective of this proposal is to elucidate the molecular mechanisms by which general anesthetics produce unconsciousness. Since ion channels mediate communication within and between cells in the CNS, they are considered likely candidates as the "targets" of anesthetics. In order to investigate molecular mechanisms of action of general anesthetics on membrane excitability in the CNS, the applicant proposes specifically to examine the effects of different anesthetics on ligand gated ion channels, including the mAChR, GABAA receptor, and the nAChR. The basic hypothesis is that anesthetics bind directly to ion channel proteins. Specific aims now include: 1) to study the effect of anesthetics on mAChR channels which have mutations within the pore of the channel in order to determine where and whether anesthetics bind within the pore; 2) to determine the effects of anesthetics on GABAA receptor channels and to see whether this is similar to the effects on AChR channels; 3) to determine whether the action of anesthetics on neuronal AChR channels is similar to the action on muscle AChR channels; and 4) to determine whether the different isoforms of neuronal AChR and GABAA receptor channels have different sensitivities to anesthetics. Transfected HEK cells containing the ligand gated ion channel of interest is the model system utilized.